Something

#include <cstdlib>
#include <iostream>
#include <fstream>

using namespace std;

int read_file(char* filename);
int write_record(FILE* fp, struct transaction& t);
int read_record(FILE* fp);

int main()
{
    
 return 0;   
}

int read_file(char* filename)
{
   FILE* fp = fopen(filename, "rb");
   if(!fp) return -1;

   while(!feof(fp))
   {
      int err = 0;
      if(err = read_record(fp)) {
         cout << "error!" << endl;
         return err;
      }
   }

   return 0;
}

int write_record(FILE* fp, struct transaction& t)
{
    
}
int read_record(FILE* fp)
{
    struct transaction_record t;
    int err = fread(fp, &t, sizeof(t));

    if(err) return err;

    cout << t.transactionID << endl;

    return 0;
}